use std::cell::RefCell;
use std::collections::HashMap;
use std::fs::OpenOptions;
use std::io::Read;
use std::net::TcpStream;

use multimap::MultiMap;

use std::sync::Arc;

use std::ops::Range;

use std::rc::Rc;

use std::ffi::OsStr;
use std::io;
use std::io::prelude::*;

pub use tera::{Context, Tera};

pub mod mime;

use hmac::Hmac;
use sha2::Sha256;

use crate::cookie::Cookie;

use serde_json::Value;
use std::collections::BTreeMap;

pub mod http_response_table {
    const STATE_TABLE: [(u16, &str); 20] = [
        (101, "101 Switching Protocals\r\n"),
        (200, "200 OK\r\n"),
        (201, "201 Created\r\n"),
        (202, "202 Accepted\r\n"),
        (204, "204 No Content\r\n"),
        (206, "206 Partial Content\r\n"),
        (300, "300 Multiple Choices\r\n"),
        (301, "301 Moved Permanently\r\n"),
        (302, "302 Moved Temporarily\r\n"),
        (304, "304 Not Modified\r\n"),
        (400, "400 Bad Request\r\n"),
        (401, "401 Unauthorized\r\n"),
        (403, "403 Forbidden\r\n"),
        (404, "404 Not Found\r\n"),
        (413, "413 Request Entity Too Large\r\n"),
        (416, "416 Requested Range Not Satisfiable\r\n"),
        (500, "500 Internal Server Error\r\n"),
        (501, "501 Not Implemented\r\n"),
        (502, "502 Bad Gateway\r\n"),
        (503, "503 Service Unavailable\r\n"),
    ];

    pub(super) fn get_httpstatus_from_code(code: u16) -> &'static str {
        match STATE_TABLE.binary_search_by_key(&code, |&(k, _)| k) {
            Ok(index) => STATE_TABLE[index].1,
            Err(_) => panic!("not supporting such a http state code"),
        }
    }

    const HTTP_METHODS: [(u8, &str); 9] = [
        (0, "GET"),
        (1, "POST"),
        (2, "OPTIONS"),
        (3, "DELETE"),
        (4, "HEAD"),
        (5, "PUT"),
        (6, "PATCH"),
        (7, "CONNECT"),
        (8, "TRACE"),
    ];
    /// > Correspond to http GET
    pub const GET: u8 = 0;
    /// > Correspond to http POST
    pub const POST: u8 = 1;
    /// > Correspond to http OPTIONS
    pub const OPTIONS: u8 = 2;
    /// > Correspond to http DELETE
    pub const DELETE: u8 = 3;
    /// > Correspond to http HEAD
    pub const HEAD: u8 = 4;
    /// > Correspond to http PUT
    pub const PUT: u8 = 5;
    /// > Correspond to http PATCH
    pub const PATCH: u8 = 6;
    /// > Correspond to http CONNECT
    pub const CONNECT: u8 = 7;
    /// > Correspond to http TRACE
    pub const TRACE: u8 = 8;
    pub fn get_httpmethod_from_code(code: u8) -> &'static str {
        match HTTP_METHODS.binary_search_by_key(&code, |&(k, _)| k) {
            Ok(index) => HTTP_METHODS[index].1,
            Err(_) => panic!("not supporting such a http state code"),
        }
    }
}
pub struct Request<'a> {
    pub(super) header_pair: HashMap<&'a str, &'a str>,
    pub(super) url: &'a str,
    pub(super) method: &'a str,
    pub(super) version: &'a str,
    pub(super) body: BodyContent<'a>,
    pub(super) conn_: Rc<RefCell<&'a mut TcpStream>>,
    pub(super) secret_key: Arc<Hmac<Sha256>>,
    pub(super) ctx: RefCell<BTreeMap<String, Value>>,
}

impl<'a> Request<'a> {
    /// Get the value of a header pair by specifying the key
    /// For example, `Content-length: 123`
    /// get_header("Content-length"), the key is not case senstive
    pub fn get_header(&self, key: &str) -> Option<&str> {
        let r = self.header_pair.keys().find(|&&ik| {
            if ik.to_lowercase() == key.to_lowercase() {
                true
            } else {
                false
            }
        });
        match r {
            Some(r) => {
                return Some(self.header_pair.get(*r).unwrap()); // confirm that unwrap() is harmless
            }
            None => {
                return None;
            }
        }
    }

    /// > Get the value of a parameter in the requested url
    /// # For example
    /// > `/path?id=1`
    /// >> - `get_param("id")` returns 1, the key is case senstive
    pub fn get_param(&self, k: &str) -> Option<&str> {
        match self.url.split_once("?") {
            Some((_, v)) => {
                let r = v.split("&");
                for e in r {
                    match e.split_once("=") {
                        Some((ik, iv)) => {
                            if ik == k {
                                return Some(iv);
                            }
                        }
                        None => {}
                    }
                }
                None
            }
            None => None,
        }
    }

    /// > Get the HashMap of the parameters in the requested url
    /// # For example
    /// > `/path?id=1&flag=true`
    /// >> - `get_params()` returns `{id:1, flag:true }`
    pub fn get_params(&self) -> Option<HashMap<&str, &str>> {
        match self.url.split_once("?") {
            Some((_, v)) => {
                let r = v.split("&");
                let mut map = HashMap::new();
                for e in r {
                    match e.split_once("=") {
                        Some((ik, iv)) => {
                            map.insert(ik, iv);
                        }
                        None => {}
                    }
                }
                if map.len() == 0 {
                    None
                } else {
                    Some(map)
                }
            }
            None => None,
        }
    }

    /// > Get the complete http headers
    /// >> - `{"Content-length":"1", "key":"value",...}`
    pub fn get_headers(&self) -> HashMap<&str, &str> {
        self.header_pair.clone()
    }
    /// > Get the version of http request
    pub fn get_version(&self) -> &str {
        self.version
    }

    /// > Query the value of www-form-urlencoded or the text part of the multipart-form
    /// >> - The key is not case senstive
    /// # For example
    /// > Assume the form has the value `id=1`, then get_query("id") returns Some("1")
    ///
    pub fn get_query(&self, k: &str) -> Option<&str> {
        if let BodyContent::UrlForm(x) = &self.body {
            let r = x.keys().find(|&&ik| {
                if ik.to_lowercase() == k.to_lowercase() {
                    true
                } else {
                    false
                }
            });
            match r {
                Some(r) => {
                    return Some(x.get(*r).unwrap()); // confirm that unwrap() is harmless
                }
                None => {
                    return None;
                }
            }
        } else if let BodyContent::Multi(x) = &self.body {
            let r = x.keys().find(|&ik| {
                if ik.to_lowercase() == k.to_lowercase() {
                    true
                } else {
                    false
                }
            });
            match r {
                Some(s) => {
                    let v = x.get(s).unwrap(); // guarantee by above
                    match v {
                        MultipleFormData::Text(v) => {
                            return Some(*v);
                        }
                        MultipleFormData::File(_) => return None,
                    }
                }
                None => {
                    return None;
                }
            }
        } else {
            None
        }
    }

    /// > This method is used to acquire the file in the multipart-form data
    /// # For example,
    /// ```
    /// <form>
    ///    <input type="file" name="file1" />
    /// </form>
    ///
    ///```
    /// > - `get_file("file1")` return the file's meta data
    pub fn get_file(&self, k: &str) -> Option<&'_ MultipleFormFile> {
        if let BodyContent::Multi(x) = &self.body {
            let r = x.keys().find(|&ik| {
                if k.to_lowercase() == ik.to_lowercase() {
                    true
                } else {
                    false
                }
            });
            match r {
                Some(s) => {
                    let item = x.get(s).unwrap(); // confirm that unwrap() is harmless
                    if let MultipleFormData::File(file) = item {
                        return Some(file);
                    } else {
                        return None;
                    }
                }
                None => return None,
            }
        } else {
            None
        }
    }

    /// > Return a HashMap that comprises all pairs in the www-form-urlencoded or the text part of the multipart-form
    /// >> - It is safety called even though the request is `GET`, which returns None
    pub fn get_queries(&self) -> Option<HashMap<&str, &str>> {
        if let BodyContent::UrlForm(x) = &self.body {
            Some(x.clone())
        } else if let BodyContent::Multi(x) = &self.body {
            let mut v = HashMap::new();
            for (k, item) in x {
                match item {
                    MultipleFormData::Text(text) => {
                        v.insert(k.as_str(), *text);
                    }
                    MultipleFormData::File(_) => {}
                }
            }
            if v.len() != 0 {
                return Some(v);
            } else {
                return None;
            }
        } else {
            None
        }
    }

    /// > Returns an array comprises of all files in the multipart-form data
    pub fn get_files(&self) -> Option<Vec<&MultipleFormFile>> {
        if let BodyContent::Multi(x) = &self.body {
            let mut vec = Vec::new();
            for (_k, v) in x {
                match v {
                    MultipleFormData::Text(_) => {}
                    MultipleFormData::File(file) => {
                        vec.push(file);
                    }
                }
            }
            if vec.len() != 0 {
                return Some(vec);
            } else {
                return None;
            }
        } else {
            None
        }
    }

    /// > Returns the body of a request
    /// >> -  it is used for getting the posted JSON or other plain text body
    pub fn plain_body(&self) -> Option<&str> {
        if let BodyContent::PureText(x) = self.body {
            Some(x)
        } else {
            None
        }
    }

    /// > Determin whether the request has a body
    pub fn has_body(&self) -> bool {
        if let BodyContent::None = self.body {
            false
        } else {
            true
        }
    }

    /// > Return the raw instance of TcpStream
    /// >> - This method should be carefully used,
    /// It is better to only get some meta information of a connection, such as a peer IP
    pub fn get_conn(&self) -> Rc<RefCell<&'a mut TcpStream>> {
        Rc::clone(&self.conn_)
    }

    /// > Return the requested http method
    pub fn get_method(&self) -> &str {
        self.method
    }

    /// > Return the complete requested url
    pub fn get_url(&self) -> &str {
        self.url
    }

    pub(crate) fn get_secret_key(&self) -> Arc<Hmac<Sha256>> {
        Arc::clone(&self.secret_key)
    }

    /// > Return the part of url exclude the parameters(if any)
    pub fn url_to_path(&self) -> &str {
        match self.url.find("?") {
            Some(pos) => &self.url[..pos],
            None => self.url,
        }
    }

    /// > It is used to store user data
    /// >> - share data between middlwares and routers(if any)
    ///
    pub fn get_context(&self) -> &RefCell<BTreeMap<String, Value>> {
        &self.ctx
    }
}

pub struct ResponseConfig<'b, 'a> {
    res: &'b mut Response<'a>,
    has_failure: bool,
}

impl<'b, 'a> ResponseConfig<'b, 'a> {
    fn get_map_key(map: &MultiMap<String, String>, key: &str) -> Option<String> {
        let r = map.keys().find(|&ik| {
            if ik.to_lowercase() == key.to_lowercase() {
                true
            } else {
                false
            }
        });
        Some((r?).clone())
    }

    /// > Set the transfer type of a response with chunked
    pub fn chunked(&mut self) -> &mut Self {
        if self.has_failure {
            return self;
        }
        if self.res.method == "HEAD" {
            return self;
        }
        self.res
            .add_header(String::from("Transfer-Encoding"), String::from("chunked"));
        if let Some(key) = Self::get_map_key(&self.res.header_pair, "content-length") {
            self.res.header_pair.remove(&key);
        }
        self.res.chunked.enable = true;
        self
    }

    /// > Specify the status of a http response
    pub fn status(&mut self, code: u16) -> &mut Self {
        if self.has_failure {
            return self;
        }
        self.res.http_state = code;
        self
    }

    /// > This is only used to specify the name when the client downloads a file
    /// >> - Only works if it follows the write_file()
    pub fn specify_file_name(&mut self, name: &str) -> &mut Self {
        if self.has_failure {
            return self;
        }
        match &self.res.body {
            BodyType::Memory(_, _) => {}
            BodyType::File(_, _) => {
                if !self.res.header_exist("Content-Disposition") {
                    self.res.add_header(
                        "Content-Disposition".to_string(),
                        format!("attachment; filename=\"{name}\""),
                    );
                }
            }
            BodyType::None => {}
        }
        self
    }

    /// > Start a range function for such as `write_file`, `write_string`, or `render_view_xxxx`
    pub fn enable_range(&mut self) -> &mut Self {
        if self.has_failure {
            return self;
        }
        self.res
            .add_header(String::from("Accept-Ranges"), String::from("bytes"));
        if self.res.method == "HEAD" {
            match &self.res.body {
                BodyType::Memory(_, buffs) => {
                    self.res
                        .add_header(String::from("Content-length"), buffs.len().to_string());
                    self.res.http_state = 200;
                }
                BodyType::File(path, _) => {
                    match std::fs::OpenOptions::new().read(true).open(path) {
                        Ok(file) => {
                            match file.metadata() {
                                Ok(meta) => {
                                    self.res.add_header(
                                        String::from("Content-length"),
                                        meta.len().to_string(),
                                    );
                                    self.res.http_state = 200;
                                }
                                Err(_) => {
                                    self.has_failure = true;
                                    self.res.write_state(404);
                                }
                            };
                        }
                        Err(_) => {
                            self.has_failure = true;
                            self.res.write_state(404);
                        }
                    }
                }
                BodyType::None => {}
            }
        } else {
            match self.res.get_request_header_value("Range") {
                Some(v) => {
                    self.res.range = parse_range_content(v);
                }
                None => {
                    self.res.range = ResponseRangeMeta::None;
                }
            }
        }
        self
    }

    /// > Specify cookies for the request
    /// >> - Argument could be a single Cookie
    /// >> - Or muliple Cookies: [Cookie,Cookie,...]
    pub fn with_cookies<T: MoreThanOneCookie<Output = Cookie>>(&mut self, v: T) -> &mut Self {
        if self.has_failure {
            return self;
        }
        for e in v.into_vec() {
            match e.to_string() {
                Some(s) => {
                    self.res.add_header(String::from("set-cookie"), s);
                }
                None => {
                    continue;
                }
            }
        }
        self
    }

    pub fn charset(&mut self, v: &str) -> &mut Self {
        if self.has_failure {
            return self;
        }
        self.res.charset = Some(v.to_string());
        self
    }
}

pub trait MoreThanOneCookie {
    type Output;
    fn into_vec(self) -> Vec<Self::Output>;
}

impl MoreThanOneCookie for Cookie {
    type Output = Cookie;

    fn into_vec(self) -> Vec<Self::Output> {
        vec![self]
    }
}

impl<const I: usize> MoreThanOneCookie for [Cookie; I] {
    type Output = Cookie;

    fn into_vec(self) -> Vec<Self::Output> {
        Vec::from(self)
    }
}

fn parse_range_content(v: &str) -> ResponseRangeMeta {
    match v.trim().split_once("=") {
        Some(v) => {
            let v = v.1;
            match v.trim().split_once("-") {
                Some(v) => {
                    let start;
                    let end;
                    if v.0 != "" {
                        let mut exception = false;
                        let r: u64 = v.0.parse().unwrap_or_else(|_| {
                            exception = true;
                            0
                        });
                        if r == 0 && exception == true {
                            start = None;
                        } else {
                            start = Some(r);
                        }
                    } else {
                        start = None;
                    }
                    if v.1 != "" {
                        let mut exception = false;
                        let r: u64 = v.1.parse().unwrap_or_else(|_| {
                            exception = true;
                            0
                        });
                        if r == 0 && exception == true {
                            end = None;
                        } else {
                            end = Some(r);
                        }
                    } else {
                        end = None;
                    }
                    ResponseRangeMeta::Range(start, end)
                }
                None => ResponseRangeMeta::Range(None, None),
            }
        }
        None => ResponseRangeMeta::Range(None, None),
    }
}

pub struct ResponseChunkMeta {
    pub(super) enable: bool,
    pub(super) chunk_size: usize,
}

impl ResponseChunkMeta {
    pub(super) fn new(chunk_size: u32) -> Self {
        ResponseChunkMeta {
            enable: false,
            chunk_size: chunk_size as usize,
        }
    }
}

pub enum ResponseRangeMeta {
    Range(Option<u64>, Option<u64>),
    None,
}

pub enum MemoryType {
    String(String),
    Binary,
}

pub enum BodyType {
    Memory(MemoryType, Vec<u8>),
    File(String, Option<String>),
    None,
}

pub struct Response<'a> {
    pub(super) header_pair: MultiMap<String, String>,
    pub(super) version: &'a str,
    pub(super) method: &'a str,
    //pub(super) url: &'a str,
    pub(super) http_state: u16,
    pub(super) body: BodyType,
    pub(super) chunked: ResponseChunkMeta,
    pub(super) conn_: Rc<RefCell<&'a mut TcpStream>>,
    pub(super) range: ResponseRangeMeta,
    pub(super) request_header: HashMap<&'a str, &'a str>,
    pub(super) charset: Option<String>,
}

impl<'a> Response<'a> {
    fn get_request_header_value(&mut self, k: &str) -> Option<&str> {
        match self.request_header.keys().find(|&&ik| {
            if k.to_lowercase() == ik.to_lowercase() {
                true
            } else {
                false
            }
        }) {
            Some(k) => Some(self.request_header.get(*k).unwrap()), // confirm that unwrap() is harmless
            None => None,
        }
    }

    /// > Remove a pair you have writed to a reponse header
    /// >> - The key is not case senstive
    /// # For example
    /// ```
    /// add_header(String::from("a"),String::from("b"))
    /// ```
    /// > Header: {a:b}
    /// ```
    /// remove_header(String::from("a"))
    /// ```
    /// > Header: {}
    pub fn remove_header(&mut self, key: String) {
        let r = self.header_pair.keys().find(|&ik| {
            if key.to_lowercase() == ik.to_lowercase() {
                true
            } else {
                false
            }
        });
        match r {
            Some(k) => {
                let s = k.clone();
                let map = &mut self.header_pair;
                map.remove(&s);
            }
            None => {}
        }
    }

    /// > Add a pair to the header of the response
    /// ```
    /// add_header(String::from("a"),String::from("b"))
    /// ```
    /// >  Header:{a:b}
    pub fn add_header(&mut self, key: String, value: String) {
        self.header_pair.insert(key, value);
    }

    fn set_default_content_type(&mut self) {
        if !self.header_exist("Content-Type") {
            match &self.body {
                BodyType::Memory(kind, _) => {
                    match kind {
                        MemoryType::String(extension) => match &self.charset {
                            Some(charset) => {
                                self.add_header(
                                    "Content-type".to_string(),
                                    format!("{}; charset={}", extension, charset),
                                );
                            }
                            None => {
                                self.add_header(
                                    "Content-type".to_string(),
                                    format!("{}; charset=utf-8", extension),
                                );
                            }
                        },
                        MemoryType::Binary => {}
                    };
                }
                BodyType::File(_, extension) => {
                    if let Some(x) = extension {
                        match &self.charset {
                            Some(charset) => {
                                self.add_header(
                                    "Content-type".to_string(),
                                    format!("{}; charset={}", x, charset),
                                );
                            }
                            None => {
                                self.add_header(
                                    "Content-type".to_string(),
                                    format!("{}; charset=utf-8", x),
                                );
                            }
                        }
                    }
                }
                BodyType::None => {}
            }
        }
    }
    pub(super) fn header_to_string(&mut self) -> Vec<u8> {
        //println!("header pairs: {:#?}",self.header_pair);
        let mut buffs = Vec::new();
        let state_text = http_response_table::get_httpstatus_from_code(self.http_state);
        buffs.extend_from_slice(format!("{} {}", self.version, state_text).as_bytes());
        self.set_default_content_type();
        for (k, v) in &self.header_pair {
            for value in v {
                buffs.extend_from_slice(format!("{}: {}\r\n", k, value).as_bytes());
            }
        }
        buffs.extend_from_slice(b"\r\n");
        buffs
    }

    fn take_body_size(&mut self) -> io::Result<u64> {
        match &self.body {
            BodyType::Memory(_, buff) => Ok(buff.len() as u64),
            BodyType::File(path, _) => match std::fs::OpenOptions::new().read(true).open(path) {
                Ok(file) => Ok(file.metadata()?.len()),
                Err(e) => Err(e),
            },
            BodyType::None => Ok(0),
        }
    }

    pub(super) fn take_body_buff(&mut self) -> io::Result<LayzyBuffers> {
        let body_size = self.take_body_size()?;
        match self.range {
            ResponseRangeMeta::Range(start, end) => {
                let mut beg_pos;
                let end_pos;
                let mut lack_beg = false;
                if let Some(x) = start {
                    beg_pos = x;
                } else {
                    beg_pos = 0;
                    lack_beg = true;
                }
                if let Some(x) = end {
                    if lack_beg {
                        end_pos = body_size - 1;
                        beg_pos = body_size - x;
                    } else {
                        end_pos = x;
                    }
                } else {
                    if lack_beg {
                        self.write_state(416);
                        return Err(io::Error::new(
                            io::ErrorKind::InvalidData,
                            "bad requested range values with form [ - ]",
                        ));
                    }
                    end_pos = body_size - 1;
                }
                if beg_pos > end_pos || (beg_pos > (body_size - 1)) || end_pos >= body_size {
                    self.write_state(416);
                    return Err(io::Error::new(
                        io::ErrorKind::InvalidData,
                        "bad requested range values due to out of range",
                    ));
                }

                let v = format!("bytes {}-{}/{}", beg_pos, end_pos, body_size);
                let len = (end_pos - beg_pos + 1).to_string();
                self.add_header(String::from("Content-Range"), v);
                let key = "Content-Length".to_string();
                self.remove_header(key.clone());

                if !self.chunked.enable {
                    self.add_header(key, len);
                }
                self.http_state = 206;

                match &self.body {
                    BodyType::Memory(_, buffs) => {
                        let slice = &buffs[beg_pos as usize..=end_pos as usize];
                        let mut ret_buff = Vec::new();
                        ret_buff.extend_from_slice(slice);
                        return Ok(LayzyBuffers {
                            buffs: LayzyBuffersType::Memory(ret_buff),
                            len: slice.len() as u64,
                        });
                    }
                    BodyType::File(path, _) => {
                        let mut file = std::fs::OpenOptions::new().read(true).open(path)?;
                        let need_size = end_pos - beg_pos + 1;
                        file.seek(std::io::SeekFrom::Start(beg_pos))?;
                        return Ok(LayzyBuffers {
                            buffs: LayzyBuffersType::File(FileType {
                                file: Box::new(file),
                                buffs: Vec::new(),
                            }),
                            len: need_size,
                        });
                    }
                    BodyType::None => {
                        return Ok(LayzyBuffers {
                            buffs: LayzyBuffersType::None,
                            len: 0,
                        });
                    }
                };
            }
            ResponseRangeMeta::None => match &self.body {
                BodyType::Memory(_, buffs) => {
                    return Ok(LayzyBuffers {
                        buffs: LayzyBuffersType::Memory(buffs.clone()),
                        len: buffs.len() as u64,
                    });
                }
                BodyType::File(path, _) => {
                    let file = std::fs::OpenOptions::new().read(true).open(path)?;
                    return Ok(LayzyBuffers {
                        buffs: LayzyBuffersType::File(FileType {
                            file: Box::new(file),
                            buffs: Vec::new(),
                        }),
                        len: body_size as u64,
                    });
                }
                BodyType::None => {
                    return Ok(LayzyBuffers {
                        buffs: LayzyBuffersType::None,
                        len: 0,
                    });
                }
            },
        }
    }

    /// > Check whether a pair exists in the header of a reponse
    /// # For example
    /// > assume the header is {a:b}
    ///
    /// `header_exist("a")` returns true
    /// > The key is not case senstive
    pub fn header_exist(&self, s: &str) -> bool {
        let r = self.header_pair.keys().find(|&k| {
            if k.to_lowercase() == s.to_lowercase() {
                true
            } else {
                false
            }
        });
        match r {
            Some(_) => true,
            None => false,
        }
    }

    /// > Get response header
    /// >> - Return a Vector since a single key can correspond to multiple values in the response header.
    pub fn get_header(&self, k: &str) -> Option<&Vec<String>> {
        self.header_pair.get_vec(k)
    }
    /// > Write a utf-8 String to client
    pub fn write_string(&mut self, v: &str) -> ResponseConfig<'_, 'a> {
        self.add_header(String::from("Content-length"), v.len().to_string());
        self.body = BodyType::Memory(MemoryType::String("text/plain".to_string()), v.into());
        ResponseConfig {
            res: self,
            has_failure: false,
        }
    }

    /// > Write binary data to client
    pub fn write_binary(&mut self, v: Vec<u8>) -> ResponseConfig<'_, 'a> {
        self.add_header(String::from("Content-length"), v.len().to_string());
        self.body = BodyType::Memory(MemoryType::Binary, v);
        ResponseConfig {
            res: self,
            has_failure: false,
        }
    }

    /// > Only respond HTTP status to the client
    pub fn write_state(&mut self, code: u16) {
        self.http_state = code;
        self.add_header(String::from("Content-length"), 0.to_string());
        self.body = BodyType::None;
    }

    /// > Write file data to the client
    pub fn write_file(&mut self, path: String) -> ResponseConfig<'_, 'a> {
        match std::fs::OpenOptions::new().read(true).open(path.clone()) {
            Ok(file) => {
                match file.metadata() {
                    Ok(meta) => {
                        self.add_header(String::from("Content-length"), meta.len().to_string());
                    }
                    Err(_) => {
                        self.write_string(&format!("{} cannot get file length", path))
                            .status(404);
                        return ResponseConfig {
                            res: self,
                            has_failure: true,
                        };
                    }
                };
                let extension = std::path::Path::new(&path)
                    .extension()
                    .and_then(OsStr::to_str);

                match extension {
                    Some(extension) => {
                        let content_type = mime::extension_to_content_type(extension);
                        self.body = BodyType::File(path, Some(content_type.to_string()));
                    }
                    None => {
                        self.body = BodyType::File(path, None);
                    }
                }
                return ResponseConfig {
                    res: self,
                    has_failure: false,
                };
            }
            Err(_) => {
                self.write_string(&format!("{} file not found", path))
                    .status(404);
                return ResponseConfig {
                    res: self,
                    has_failure: true,
                };
            }
        }
    }

    /// > Render a view to the client
    /// >> - factory implements Fn() -> tera::Result<String>
    /// >>> - The factory permits you customize the behavior of the tera engine
    pub fn render_view(
        &mut self,
        factory: impl Fn(&Request) -> tera::Result<String>,
        context: &Request,
    ) -> ResponseConfig<'_, 'a> {
        match factory(context) {
            Ok(s) => {
                return self.write_string(&s);
            }
            Err(e) => {
                self.write_string(&format!("Render view error: {}", e.to_string()))
                    .status(404);
                return ResponseConfig {
                    res: self,
                    has_failure: true,
                };
            }
        }
    }

    /// > Only use the default configured tera to render a view to the client
    /// >> - path: path of view file
    /// >> - context: used in the view
    pub fn render_view_once(&mut self, path: &str, context: &Context) -> ResponseConfig<'_, 'a> {
        match OpenOptions::new().read(true).open(path) {
            Ok(mut file) => {
                let mut s = String::new();
                match file.read_to_string(&mut s) {
                    Ok(_) => match Tera::one_off(&s, &context, true) {
                        Ok(s) => {
                            self.add_header(String::from("Content-length"), s.len().to_string());
                            let extension = std::path::Path::new(&path)
                                .extension()
                                .and_then(OsStr::to_str);

                            match extension {
                                Some(extension) => {
                                    let content_type = mime::extension_to_content_type(extension);
                                    self.body = BodyType::Memory(
                                        MemoryType::String(content_type.to_string()),
                                        s.into(),
                                    );
                                }
                                None => {
                                    self.body = BodyType::Memory(
                                        MemoryType::String("text/plain".to_string()),
                                        s.into(),
                                    );
                                }
                            }
                            return ResponseConfig {
                                res: self,
                                has_failure: false,
                            };
                        }
                        Err(e) => {
                            self.write_string(&format!("Render view error: {}", e.to_string()))
                                .status(404);
                            return ResponseConfig {
                                res: self,
                                has_failure: true,
                            };
                        }
                    },
                    Err(e) => {
                        self.write_string(&format!("Render view error: {}", e.to_string()))
                            .status(404);
                        return ResponseConfig {
                            res: self,
                            has_failure: true,
                        };
                    }
                }
            }
            Err(e) => {
                self.write_string(&format!("Render view error: {}", e.to_string()))
                    .status(404);
                return ResponseConfig {
                    res: self,
                    has_failure: true,
                };
            }
        }
    }

    pub fn get_conn(&self) -> Rc<RefCell<&'a mut TcpStream>> {
        Rc::clone(&self.conn_)
    }
}

#[derive(Debug)]
pub enum BodyContent<'a> {
    UrlForm(HashMap<&'a str, &'a str>),
    PureText(&'a str),
    Multi(HashMap<String, MultipleFormData<'a>>),
    None,
    Bad,
    TooLarge,
}

#[derive(Debug)]
pub struct MultipleFormFile {
    pub filename: String,
    pub filepath: String,
    pub content_type: String,
    pub form_indice: String,
}

#[derive(Debug)]
pub enum MultipleFormData<'a> {
    Text(&'a str),
    File(MultipleFormFile),
}

pub(super) struct FileType {
    file: Box<std::fs::File>,
    buffs: Vec<u8>,
}

pub(super) enum LayzyBuffersType {
    Memory(Vec<u8>),
    File(FileType),
    None,
}
pub(super) struct LayzyBuffers {
    buffs: LayzyBuffersType,
    len: u64,
}

impl LayzyBuffers {
    pub fn len(&self) -> usize {
        self.len as usize
    }

    pub fn get_slice_from_range(&mut self, index: Range<usize>) -> Result<&[u8], io::Error> {
        match &mut self.buffs {
            LayzyBuffersType::Memory(buffs) => Ok(&mut buffs[index]),
            LayzyBuffersType::File(file_v) => {
                let file = &mut file_v.file;
                let need_size = index.end - index.start;
                let buffs = &mut file_v.buffs;
                buffs.resize(need_size, b'\0');
                match file.read(&mut buffs[0..]) {
                    Ok(read_size) => {
                        if read_size != need_size {
                            let msg = format!("cannot read enough bytes from the file, need bytes: {}, actual read bytes: {}",need_size,read_size);
                            return Err(io::Error::new(io::ErrorKind::InvalidData, msg));
                        }
                        return Ok(&buffs[0..read_size]);
                    }
                    Err(e) => {
                        return Err(e);
                    }
                }
            }
            LayzyBuffersType::None => unreachable!(),
        }
    }

    // pub fn get_total_slice(& mut self)-> Result<&[u8],io::Error> {
    //     match &mut self.buffs {
    //         LayzyBuffersType::Memory(buffs) => {
    // 			return Ok(buffs);
    // 		},
    //         LayzyBuffersType::File(file_v) => {
    //             let file = &mut file_v.file;
    //             let buffs = &mut file_v.buffs;
    //             match file.read_to_end(buffs){
    //                 Ok(_) => {
    // 					return Ok(buffs);
    // 				},
    //                 Err(e) => {
    // 					return Err(e);
    // 				},
    //             }
    //         }
    //         LayzyBuffersType::None => unreachable!(),
    //     }
    // }
}

// impl Index<Range<usize>> for LayzyBuffers {
//     type Output = [u8];

//     fn index(&self, _index: Range<usize>) -> &Self::Output {
//         unreachable!()
//     }
// }

// impl IndexMut<Range<usize>> for LayzyBuffers {
//     fn index_mut(&mut self, index: Range<usize>) -> &mut Self::Output {
//         match &mut self.buffs {
//             LayzyBuffersType::Memory(buffs) => &mut buffs[index],
//             LayzyBuffersType::File(file_v) => {
//                 let file = &mut file_v.file;
//                 let need_size = index.end - index.start;
//                 let buffs = &mut file_v.buffs;
//                 buffs.resize(need_size, b'\0');
//                 file.read(buffs).unwrap();
//                 buffs
//             }
//             LayzyBuffersType::None => unreachable!(),
//         }
//     }
// }

// impl Deref for LayzyBuffers {
//     type Target = Vec<u8>;

//     fn deref(&self) -> &Self::Target {
//         unreachable!()
//     }
// }

// impl DerefMut for LayzyBuffers {
//     fn deref_mut(&mut self) -> &mut Self::Target {
//         match &mut self.buffs {
//             LayzyBuffersType::Memory(buffs) => buffs,
//             LayzyBuffersType::File(file_v) => {
//                 let file = &mut file_v.file;
//                 let buffs = &mut file_v.buffs;
//                 file.read_to_end(buffs).unwrap();
//                 buffs
//             }
//             LayzyBuffersType::None => unreachable!(),
//         }
//     }
// }